// Copyright 2017 The Draco Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
#ifndef DRACO_METADATA_GEOMETRY_METADATA_H_
#define DRACO_METADATA_GEOMETRY_METADATA_H_

#include "draco/metadata/metadata.h"

namespace draco {

// Class for representing specifically metadata of attributes. It must have an
// attribute id which should be identical to it's counterpart attribute in
// the point cloud it belongs to.
class AttributeMetadata : public Metadata {
  public:
    AttributeMetadata() : att_unique_id_(0) {}
    explicit AttributeMetadata(const Metadata &metadata)
        : Metadata(metadata), att_unique_id_(0) {}

    void set_att_unique_id(uint32_t att_unique_id) {
        att_unique_id_ = att_unique_id;
    }
    // The unique id of the attribute that this metadata belongs to.
    uint32_t att_unique_id() const {
        return att_unique_id_;
    }

  private:
    uint32_t att_unique_id_;

    friend struct AttributeMetadataHasher;
    friend class PointCloud;
};

// Functor for computing a hash from data stored in a AttributeMetadata class.
struct AttributeMetadataHasher {
    size_t operator()(const AttributeMetadata &metadata) const {
        size_t hash = metadata.att_unique_id_;
        MetadataHasher metadata_hasher;
        hash = HashCombine(metadata_hasher(static_cast<const Metadata &>(metadata)),
                           hash);
        return hash;
    }
};
// Class for representing the metadata for a point cloud. It could have a list
// of attribute metadata.
class GeometryMetadata : public Metadata {
  public:
    GeometryMetadata() {};
    explicit GeometryMetadata(const Metadata &metadata) : Metadata(metadata) {}

    const AttributeMetadata *GetAttributeMetadataByStringEntry(
        const std::string &entry_name, const std::string &entry_value) const;
    bool AddAttributeMetadata(std::unique_ptr<AttributeMetadata> att_metadata);

    void DeleteAttributeMetadataByUniqueId(int32_t att_unique_id) {
        for (auto itr = att_metadatas_.begin(); itr != att_metadatas_.end();
                ++itr) {
            if (itr->get()->att_unique_id() == att_unique_id) {
                att_metadatas_.erase(itr);
                return;
            }
        }
    }

    const AttributeMetadata *GetAttributeMetadataByUniqueId(
        int32_t att_unique_id) const {
        // TODO(zhafang): Consider using unordered_map instead of vector to store
        // attribute metadata.
        for (auto &&att_metadata : att_metadatas_) {
            if (att_metadata->att_unique_id() == att_unique_id) {
                return att_metadata.get();
            }
        }
        return nullptr;
    }

    AttributeMetadata *attribute_metadata(int32_t att_unique_id) {
        // TODO(zhafang): Consider use unordered_map instead of vector to store
        // attribute metadata.
        for (auto &&att_metadata : att_metadatas_) {
            if (att_metadata->att_unique_id() == att_unique_id) {
                return att_metadata.get();
            }
        }
        return nullptr;
    }

    const std::vector<std::unique_ptr<AttributeMetadata>> &attribute_metadatas()
    const {
        return att_metadatas_;
    }

  private:
    std::vector<std::unique_ptr<AttributeMetadata>> att_metadatas_;

    friend struct GeometryMetadataHasher;
};

// Functor for computing a hash from data stored in a GeometryMetadata class.
struct GeometryMetadataHasher {
    size_t operator()(const GeometryMetadata &metadata) const {
        size_t hash = metadata.att_metadatas_.size();
        AttributeMetadataHasher att_metadata_hasher;
        for (auto &&att_metadata : metadata.att_metadatas_) {
            hash = HashCombine(att_metadata_hasher(*att_metadata), hash);
        }
        MetadataHasher metadata_hasher;
        hash = HashCombine(metadata_hasher(static_cast<const Metadata &>(metadata)),
                           hash);
        return hash;
    }
};

}  // namespace draco

#endif  // THIRD_PARTY_DRACO_METADATA_GEOMETRY_METADATA_H_
